New synthesis of heteroglycoclusters from p-t-butylcalix[4]arene tetraalkoxyheterohalides as key intermediates
Résumé
A straightforward synthesis of heteroglycoclusters based p-t-butylcalix[4]arene has been achieved. The key step is the formation of hetero-halopentyloxy-p-t-butylcalix [4]arene mixture via haloalkylation with 1-bromo-5-chloropentane as asymmetric alkylating reagent. Subsequent selective exchange of bromide by azide under mild conditions provides selectively azido-chloro species suitable for click reaction with first propargylglycoside. The products here can then be subjected to further azidation to enable attachment of different glycosides via click chemistry reaction. [GRAPHICS] .